Various cellular radio or mobile telephone systems are presently in use to provide high quality, mobile communications over wide coverage areas. One such system is the digital mobile telephone system GSM (Groupe Special Mobile). Developments to the GSM standard are made within the European Telecommunication Standard Institute (ETSI) under the Special Mobile Group (SMG) technical committee. SMG has released the "GSM Technical Specifications" which are available from the Publications Office of ETSI, and are incorporated herein by reference as though set forth in full. The spectrum of applications which use GSM technology is extremely broad. For example, the applications include handheld, portable, transportable, PCMCIA, PC, PDA, Organizer, adapter cards, modems and other systems where GSM Mobile Station functionality is performed partly or completely.
Because of the wide variety of applications, the ability to implement new end-user services, Man Machine Interfaces (MMI) and various types of media into a GSM architecture is vital for commercial products. Moreover, to implement the GSM standard, numerous individual circuit modules are required to provide the resources to address the various functions supported by GSM. Therefore, to increase the versatility and cost effectiveness of a GSM product, it is desirable that the architecture efficiently share common resources. Also, since mobility is at issue, it is desirable that the physical size of the product be as small as possible.
In conventional GSM products, the modules for performing the functions required in a GSM system are typically discrete electrical circuits which are interconnected on a circuit board. Detailed examples of GSM modules are well known to those with skill in the art and are described in, for example, Mouly and Pautet, "The GSM System for Mobile Communications", (1992) (published by the authors) International Standard Book Number 2-9507190-0-7, incorporated herein by reference as though set forth in full. However, this type of system construction is limited with respect to the flexibility it can offer for adding new interfaces and MMI because changes to the functionality of the modules may require the architecture of the board to be re-designed. Additionally, it is also limited with respect to physical size by the space requirements of the mounted components. Therefore, it is an object of the present invention to provide a solution to the above mentioned problems, and to provide further advantages over the current art as will become clear in view of the following disclosure.